Wait to Start time question

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Dec 20, 2004 | 10:27 PM

WheredaFoxhat

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From: Fairmount, Ont.

Wait to Start time question

How long should the "wait to stat light" run on a 97 PSD? I was looking at one this weekend and the light was on for 5 seconds at the most. Guy said that if the truck was warm, it didn't stay on long. Another (usually more trustworthy) source said that at least 20 seconds regardless of engine temp. Which one is right?

Dec 20, 2004 | 10:33 PM

97xsport

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I copied this straight out of the book for you, hope it helps.

The Navistar engine control system includes a Glow Plug Control System that controls the current flow to the glow plugs. Glow plug relay "ON" time is controlled by the ECM and is a function of Engine Coolant Temperature, Barometric Pressure, and Battery Voltage. Glow plug "ON" time varies between 10-120 seconds. Glow plugs are self limiting glow plugs and do not require to be cycled on and off. The glow plug relay will cycle on and off repeatedly, if battery voltage is greater than 13.0 volts.

NOTE: Wait light on time is independent from glow plug relay on time

Dec 21, 2004 | 03:27 AM

fedextech

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97xsport is right on the money. also the book says...you do not have to wait till the light goes off to start the engine. a psd in good shape will start right up in temps as low as 20 degrees f. ( straight from the ford owners manual) my '99 f350 psd 130,000 has always started right up ! kick the tires and light the fires! these engines are widely used in the fire dept and ems service and pick up and delivery services...and are started up instantly and constantly day after day. why wait? the battery is hot, crank it right away instead of letting the glow plugs pull it down...lower voltage is harder on the starter ( draws more amps ). starters are not cheap ! crank it up !

Dec 21, 2004 | 08:10 AM

WheredaFoxhat

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From: Fairmount, Ont.

Thanks, but that does not answer my intended question. How long should the "wait to start" light be on for? The reason I ask is because I was told that a short cycling WTS light indicates other electrical problems (maybe bad glow plugs etc). While I do appreciate the replys, I was curious about the time for the WTS lamp and it's implications, not the cycling of the glow plugs. Sorry for any confusion, and thanks for your time.

Peter.

Dec 21, 2004 | 08:18 AM

Frobozz

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The WTS light stays on longer based on conditions like how cold it is outside and how cold the engine is. On a warm engine it doesn't stay on very long at all. Like others have said, there is no direct relationship between the light and the glowplugs.

I believe the WTS light not coming on *at all* is an indicator of PCM and/or fuse troubles. Or if it just flickers on briefly when it's 20 degrees out and the engine has been sitting for a day, that would also be suspicious. But under warm-engine conditions, there is nothing unusual about a WTS light that only stays on a second or two.

Duncan

Dec 21, 2004 | 08:29 AM

The Grinch

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From: Cleveland Area

The WTS is based on the engine temp (whether it is warm or cold) and the outside temp. Cold engine, cold outside - WTS stays on longer than Warm eng and cold outside or warm eng and warm outside. I would not try and start it until the light goes out though. The light going out is telling you the temp in the combustion chamber is sufficient for the truck to compression fire and run. If yuo do not wait for the WTS light to go out, it may start but if it is cold I would doubt it will start, and based on Batt. Cond. you may only have the one chance. The glow plugs themselves stay on for 2 minutes after the ignition is turned on. What this does is if you turn on the ignition and wait for the WTS light to go out, you can wait a few more seconds, I normally count to 5 if it is cold, then I start. It allows the comb. chamber to be just a bit warmer and more ensure a good start.

Dec 21, 2004 | 08:31 AM

The Grinch

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From: Cleveland Area

Also, if you can, plug the truck in if it will be cold overnight or even during nonuse in the day. I leave mine plugged in all the time I can when it is cold ( under 32 deg. F), that way it is always ready, and the WTS light goes out faster and she starts a lot easier.